Preload judgement device and preload judgement method

Abstract

A preload judgement device includes: a preload obtaining unit configured to obtain a preload that acts on a bearing that pivotally supports a drive shaft of a motor; and a notification unit configured to give notification that the preload is not appropriate when the obtained preload is not in a set range.

What is claimed is: 
     
         1 . A preload judgement device comprising:
 a preload obtaining unit configured to obtain a preload that acts on a bearing that pivotally supports a drive shaft of a motor; and   a notification unit configured to give notification that the preload is not appropriate when the obtained preload is not in a set range.   
     
     
         2 . The preload judgement device according to  claim 1 , wherein the preload obtaining unit is a load sensor disposed between a side surface of the bearing in a rotary axis direction and a housing of the motor. 
     
     
         3 . The preload judgement device according to  claim 2 , wherein the load sensor is disposed between an outer race of the bearing and the housing. 
     
     
         4 . The preload judgement device according to  claim 1 , wherein a spindle of a machine tool is connected to the drive shaft through a coupling. 
     
     
         5 . The preload judgement device according to  claim 4 , wherein the notification unit is further configured to give notification that the connection between the drive shaft and the spindle is not properly made when the obtained preload is not in the set range. 
     
     
         6 . A preload judgement method comprising:
 a preload obtaining step of obtaining a preload that acts on a bearing that pivotally supports a drive shaft of a motor; and   a notification step of controlling a notification unit to give notification that the preload is not appropriate when the obtained preload is not in a set range.   
     
     
         7 . The preload judgement method according to  claim 6 ,
 wherein a spindle of a machine tool is connected to the drive shaft through a coupling, and   the notification step controls the notification unit so as to give notification that the connection between the drive shaft and the spindle is not properly made when the obtained preload is not in the set range.